In 2010, a large outbreak of rotavirus gastroenteritis occurred in the Alice Springs region of the Northern Territory, Australia. The outbreak occurred 43 months after the introduction of the G1P rotavirus vaccine Rotarix®. Forty-three infants were hospitalized during the outbreak and analysis of fecal samples from each infant revealed a G1P rotavirus strain. The outbreak strain was adapted to cell culture and neutralization assays were performed using VP7 and VP4 neutralizing monoclonal antibodies. The outbreak strain exhibited a distinct neutralization resistance pattern compared to the Rotarix® vaccine strain. Whole genome sequencing of the 2010 outbreak virus strain demonstrated numerous amino acid differences compared to the Rotarix® vaccine strain in the characterized neutralization epitopes of the VP7 and VP4 proteins. Phylogenetic analysis of the outbreak strain revealed a close genetic relationship to global strains, in particular RVA/Human-wt/BEL/BE0098/2009/G1P and RVA/Human-wt/BEL/BE00038/2008/G1P for numerous genes. The 2010 outbreak strain was likely introduced from a globally circulating population of strains rather than evolving from an endemic Australian strain. The outbreak strain possessed antigenic differences in the VP7 and VP4 proteins compared to the Rotarix® vaccine strain. The outbreak was associated with moderate vaccine coverage and possibly low vaccine take in the population.
Donato, C., Cowley, D., Snelling, T., Akopov, A., Kirkness, E., & Kirkwood, C. (2014). Characterization of a G1P rotavirus causing an outbreak of gastroenteritis in the Northern Territory, Australia, in the vaccine era. Emerging Microbes and Infections, 3, 1-6. [e47]. https://doi.org/10.1038/emi.2014.47